Survey of some macroinvertebrates and physico-chemical properties in Tanat River, Wales-UK

الملخص AR

In October of 2006, chemical and physical data was collected at eight sites along the, near the town of Llangynog in Wales to observe how the chemical and physical properties of the Tanat River evolve and migrate as it flows downstream.

In addition to physical and chemical data, macroinvertebrates were collected at each site in order to determine if the “river continuum concept”, a concept which suggests that biotic communities are “predictably positioned” in a river system in direct response to certain factors including physical gradient, geomorphic features, light input, and particulate matter, was applicable along the Tanat River.

Analysis of the data revealed that physical and chemical properties of the Tanat River followed a predictable pattern with slope and velocity decreasing over the stream gradient, and temperature, conductivity, discharge, and hardness all increasing as the stream migrated.

Data from macroinvertebrate sampling revealed the abundance of collector/scraper species increased as the stream moved downstream; however, the data did not reveal a true pattern of community placement for all macroinvertebrate feeding groups.

Overall, the “river continuum concept” appears to be applicable to the Tanat River when considering physical and chemical properties of the river as it moves downstream; however, macroinvertebrate communities along the Tanat River do not appear to exhibit a predictable pattern.

Keywords: macroinvertebrates, river continuum concept, Tanat River, stream gradient, physico- Chemical properties.